This study validated nutrient sufficiency ranges (NSRs) for corn (Zea mays) at early growth stages as reported in the Southern Cooperative Series Bulletin #394. Field experiments from 2020–2022 tested the adequacy of existing NSR thresholds under varying nutrient regimes. Results indicated that nearly half of samples meeting all NSRs did not achieve expected biomass levels, suggesting that current NSRs may not be reliable for early growth diagnosis. The findings highlight the need to refine and validate NSRs for more accurate nutrient management in corn production.